Can a Will be challenged due to dementia or Alzheimer’s? Understanding the legal position

As life expectancy rises and diagnoses of dementia and Alzheimer’s disease become more common, capacity challenges are becoming a central issue in contentious probate claims. 

We’re seeing an increasing number of disputes arising from concerns about a testator’s ability to understand and approve the contents of their Will, which is a fundamental requirement for validity.

Resolving these claims often involves a detailed review of the available evidence, including medical records and the circumstances surrounding the Will's preparation.

Here, Danielle Pawson and Lucy Baines explore why this trend matters and what it means for future litigation.

Why capacity matters

Under English law, a testator must have testamentary capacity when making a Will. 

This means that they must understand the:

1. nature of making a Will and its effect
2. extent of the property that they’re disposing of
3. claims of those who might expect to benefit.
    

They must also not be suffering from any disorder of the mind that could impact their ability to make those decisions. 

Therefore, conditions such as dementia and Alzheimer’s can lead to disputes over whether a testator truly had the necessary testamentary capacity to make a Will.

How do the courts assess capacity?

The leading authority remains Banks v Goodfellow (1870), which sets out the legal test for capacity. However, applying this test in modern cases is rarely straightforward. Medical evidence, timing of diagnosis and the circumstances in which the Will was executed all play a critical role.

The recent case of Leonard v Leonard [2024] EWHC 321 highlights that even relatively early or moderate cognitive impairment can prompt close judicial scrutiny of whether a testator properly understood the nature and effect of their Will. This creates fertile ground for litigation, particularly where significant assets or complex family dynamics are involved and the primary witness (i.e. the testator) has since died.

What issues commonly arise in capacity disputes?

Capacity challenges are rarely limited to a single issue. 

These disputes often involve:

• Allegations that the testator lacked capacity at the time of execution.
• Claims of undue influence, especially where vulnerability is a factor.
• Requests for disclosure of medical records and expert evidence.

The courts must balance respect for autonomy with the need to protect those who are genuinely incapable of making informed decisions.

How can the risk of a future challenge be reduced? Practical steps for testators & practitioners

While disputes can’t always be avoided, there are steps that may help to reduce the likelihood of a future challenge.

These include:

• Obtaining a medical opinion at the time that a Will is prepared and where capacity might be questioned.
• Ensuring that detailed attendance notes are kept by the drafting solicitor.
• Considering involving an experienced contentious probate lawyer early if concerns arise.

Talk to us

If you’re facing a dispute over testamentary capacity or want to safeguard your own estate planning against future challenges, our specialist contentious probate team can help.

We specialise in disputes that relate to the validity of Wills, Inheritance Act claims for financial provision, trustee and executor disputes, as well as any issues that arise in the interpretation of Wills or the administration of estates. 

To discuss how we can support you, call 0333 004 4488, email inheritance@brabners.com or fill in our contact form.